The U3507 code indicates that a control module’s input power B circuit is experiencing intermittent or erratic voltage. This means the module is not receiving a steady power supply from the battery or alternator, which can cause the module to reset or behave unpredictably.
Physical damage, corrosion, or wear in the harness can cause voltage drops or intermittent contact.
A corroded or loose terminal in the module’s power connector can create an unreliable power path.
Low battery voltage or alternator failure can lead to erratic input power to the module.
An internal defect in the module’s power regulation circuitry can intermittently cut power.
In rare cases, a fault in the main control module can cause intermittent power, but this is less common than wiring issues.
Replacing the PCM is rarely the correct solution. The code usually points to wiring, connector, or power supply problems, not a faulty PCM.
It refers to the specific voltage rail that supplies power to a particular control module; “B” is a designation used by the manufacturer.
Yes, if the wiring or connector is the root cause, repairing or replacing the damaged section will eliminate the intermittent power issue.